A group of researchers requests funds to purchase an Eiger2 X 16M state-of- the-art pixel array detector for synchrotron-based macromolecular crystallography. All the researchers are members of the user community of the Life Sciences Collaborative Access Team (LS-CAT) at the Advanced Photon Source (APS), a third generation synchrotron source that will soon be upgraded to the next generation source. The new detector will form part of LS-CAT and will expand its capabilities significantly. The new Eiger2 X 16M detector is optimized for the brightest synchrotrons and ensure optimal use of the very bright x-ray beam after the upcoming APS upgrade. The detector is a versatile instrument that will help accomplish two major goals: a) better data quality due to the higher dynamic range of the Eiger2 detector, and 2) adoption of better data collection strategies optimized for challenging problems. The proposed instrument is ideally suited for the research purposes of the user community and will ensure that the user community at LS-CAT remains at the forefront of modern approaches to the study of biological macromolecules. In addition, the new detector will be available to the larger structural biology community as LS-CAT devotes 25% of the available time to outside users. The major and minor users comprise several active and productive laboratories with well-supported research programs that will benefit immediately from the proposed detector.